PALA (NSC 224131) has been used at a dose of 1500 mg/sq.m IV daily for 5 days for patients with metastatic adenocarcinoma of the colon or rectum. Twenty-one patients have been treated to date, 6 of whom have had no prior chemotherapy, with the remainder being treated after failure of other chemotherapeutic agents. No patient has shown regression of disease enough to qualify for a partial remission. There have been two patients who have shown stabilization of disease for periods up to 6 months. The predominant toxicities seen with PALA have been diarrhea and erythematous skin rash which has been seen in every patient. Myelosuppression has not been a problem. PALA has yet to show activity in patients with metastatic carcinoma of the colon or rectum.